Approval sheet
WF25P, WF20P, WF10P, WF12P, WF08P,
WF06P, WF04P
5%, 1%, 0.5%, 0.1%
1Ω ~ 10MΩ
Thick Film High Power Chip Resistors
Size 2512 2W, 2010 1W, 1210 1/2W,
1206 1/2W, 0805 1/4W, 0603 1/8W, 0402 1/8W
*Contents in this sheet are subject to change without prior notice.
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ASC_WFxxP_V03
MAR - 2017
Approval sheet
FEATURE
1.
2.
3.
4.
5.
High power rating and compact size
High reliability and stability
Reduced size of final equipment
RoHS compliant and Lead free products
Flame Retardant
APPLICATION
Power supply
PDA
Digital meter
Computer
Automotives
Battery charger
DC-DC power converter
DESCRIPTION
The resistors are constructed in a high grade ceramic body (aluminum oxide). Internal metal electrodes are
added at each end and connected by a resistive paste that is applied to the top surface of the substrate. The
composition of the paste is adjusted to give the approximate resistance required and the value is trimmed to
nominated value within tolerance which controlled by laser trimming of this resistive layer.
The resistive layer is covered with a protective coat. Finally, the two external end terminations are added. For
ease of soldering the outer layer of these end terminations is a Tin (lead free) alloy.
Fig 1. Construction of Chip-R
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ASC_WFxxP_V03
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Approval sheet
QUICK REFERENCE DATA
Item
Series No.
Size code
Resistance
Tolerance
Resistance
Range
TCR (ppm/C)
10 ~ 1M
< 10
Max.
dissipation at
T
amb
=70C
Max.
Operation
Voltage
Max. Overload
Voltage
Operation
Temperature
Note :
1.
2.
This is the maximum voltage that may be continuously supplied to the resistor element, see “IEC publication
60115-8”
Max. Operation Voltage : So called RCWV (Rated Continuous Working Voltage) is determined by
General Specification
WF25P
2512
(6432)
WF20P
2010
(5025)
WF10P
1210
(3225)
WF12P
1206
(3216)
5%
(E24)
0Ω,1 ~ 1M
0Ω,1 ~ 10M
0Ω,1 ~ 1M
WF08P
0805
(2012)
( E24+E96),
WF06P
0603
(1608)
WF04P
0402
(1005)
1%, 0.5%, 0.1%
±100
±100
2W
±100
±100
1W
±100
±100
1/2 W
±100
±200
1/2W
±100
±150
1/4 W
±100
±150
1/8 W
±100
-200/+400
1/8 W
300V
200V
200V
200V
150V
50V
50V
500V
400V
400V
400V
- 55/+155’C
300V
100V
100V
RCWV
½
RatedPower
Resistance Value
or Max. RCWV listed above, whichever is lower.
3.
2W loading with total solder-pad and trace size of 300 mm
2
TEST CONDITION FOR JUMPER (0
)
Item
Power Rating
Resistance
Rated Current
Peak Current
Operating
Temperature
WF25P
2W
Max. 20m
WF20P
1W
Max. 20m
WF10P
1/2W
Max. 20m
WF12P
1/2W
Max. 20m
WF08P
1/4W
Max. 20m
WF06P
1/8W
Max. 20m
WF04P
1/8W
Max. 50m
10A
25A
7A
17.5A
5A
12.5A
5A
12.5A
-55 ~ +155C
4A
10A
2A
5A
1.5A
3.8A
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ASC_WFxxP_V03
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Approval sheet
MECHANICAL DATA
Unit: mm
Symbol
L
W
T
Tt
Tb
WF25P
6.30
0.20
3.10
0.20
0.60
0.15
0.60
0.25
1.80
0.25
WF20P
5.00
0.20
2.50
0.20
0.60
0.10
0.60
0.25
0.60
0.25
WF12P
3.10
0.15
1.60
0.15
0.55
0.10
0.50
0.25
0.50
0.25
WF10P
3.10
0.15
2.50
0.15
0.55
0.10
0.50
0.25
0.50
0.25
WF08P
2.00
0.10
1.25
0.10
0.50
0.15
0.40
0.20
0.40
0.20
WF06P
1.60
0.10
0.80
0.10
0.45
0.15
0.30
0.10
0.30
0.15
WF04P
1.00
0.05
0.50
0.05
0.35
0.05
0.20
0.10
0.25
0.10
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ASC_WFxxP_V03
MAR - 2017
Approval sheet
Recommended Solder Pad Dimensions
D
W
Type
WF25P
L
W
3.7
mm
D
2.45
mm
L
7.6
mm
MARKING
For 0603 above size, each resistor is marked with a four-digit for 1% tolerance and three-digit for 5%
tolerance on the protective coating to designate the nominal resistance value.
For 0603, each resistor is marked with a three-digit!
For 0402, no marking !
For Jumper, 2512/2010 defines 0000, 1206/0805/0603 defines 000.
Example:
102 = 1k
16R0 = 16
16R0
102
FUNCTIONAL DESCRIPTION
Product characterization
Standard values of nominal resistance are taken from the E96 & E24 series for resistors with a tolerance of
5%
&
1%.
The values of the E24/E96 series are in accordance with “IEC publication 60063”.
Derating curve
The power that the resistor can dissipate depends on the operating temperature; see Fig.2
Figure 2
Maximum dissipation in percentage of rated power as a
function of the ambient temperature
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ASC_WFxxP_V03
MAR - 2017
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